I think standalone is the most outstanding advantage. Many recordings of terminal are using asciiema or youtube, those links in a github readme.md file is a static screenshot instead of animated one, you have to click the link to watch the animation.

You can view the animation without javascript enabled, and it's media type is image, you don't even need to convert it to base64 to use it. It's like gif but relatively smaller and with more colors, and it's Scalable Vector.